Poloxamine 1107 sealing of radiopermeabilized erythrocyte membranes

Purpose: Lipid peroxidation-mediated permeabilization of cell membranes fol lowing intense ionizing irradiation is well documented. This form of membra ne radiopermeabilization leads to rapid exhaustion of cellular high-energy compounds, resulting in the acute onset of cellular necrosis. Strategies to reverse the process of necrosis and preserve cell viability require membra ne sealing. This report documents the relative efficacy of Poloxamine 1107, a non-ionic surfactant, compared with other polymers, in sealing radioperm eabilized cell membranes. Materials and methods: Isolated erythrocytes were exposed to 600 Gy Co-60 i rradiation at a dose rate of 1.3 Gy/s. Different polymer compounds were add ed 10min later to the irradiated cell suspensions. At 2h later die haemoglo bin content in the supernatants was determined spectrophotometrically. Results: Compared with the non-treated irradiated control, Poloxamine 1107 significantly reduced the leakage of haemoglobin from irradiated erythrocyt es. Poloxamer 188 and dextran at equal concentrations had no significant re verse effect on the irradiation-mediated increased membrane permeability. T he amount of haemoglobin released From irradiated erythrocytes was inversel y related to the Poloxamine 1107 concentration. Conclusions: This study demonstrates the capability of Poloxamine 1107 to s eal radiopermeabilized cell membranes. Thus, surfactants such as Poloxamine 1107 might be useful as a therapeutic agent in the treatment of high-dose radiation injuries since cellular necrosis due to metabolic exhaustion foll owing radiopermeabilization of their membranes might be prevented.